Outcome of astigmatism correction using femtosecond laser combined with cataract surgery: penetrating vs intrastromal incisions.

Abstract

PURPOSE:

To compare the effectiveness of penetrating vs intrastromal femtosecond laser corneal relaxing incisions (CRIs) in reducing corneal astigmatism during cataract surgery.

SETTINGS:

Baylor College of Medicine and Mercy Clinic Eye Specialists.

DESIGN:

Prospective randomized study.

METHODS:

248 eyes from 248 patients were included. Patients were randomly assigned to undergo paired penetrating (8 mm optical zone [OZ] at 1 center and 9 mm OZ at the other) or intrastromal CRIs (8 mm OZ at both centers). The lengths of the CRIs were based on published nomograms but modified to take into account posterior corneal astigmatism. Vector analysis was performed, and net corneal changes along the CRI meridian were calculated. Multiple regression analysis was performed to assess factors contributing to net corneal changes.

RESULTS:

Preoperatively, 9% to 18% of eyes had corneal astigmatism of ≤0.5 diopters (D), and 76% to 93% of eyes had postoperative refractive astigmatism of ≤0.5 D ( P < .05). Both penetrating and intrastromal CRIs produced significant mean net corneal changes along the CRI meridian (-0.49 to -1.21 D), and 71% to 84% of eyes had postoperative astigmatism vector prediction errors of ≤0.50 D. The 8 mm penetrating CRIs induced greater net corneal changes but more eyes with overcorrection than did the intrastromal and 9 mm penetrating CRIs (all P < .05). Greater net corneal changes occurred with longer CRI length, higher preoperative corneal astigmatism magnitude, and preoperative against-the-rule corneal astigmatism. Nomograms based on anterior and total corneal astigmatism are proposed.

CONCLUSIONS:

Both penetrating and intrastromal CRIs were effective in reducing corneal astigmatism during cataract surgery.

• Authors: Li Wang, Wendell Scott, Ildamaris Montes de Oca, Douglas D Koch, Shachar Tauber, Zaina Al-Mohtaseb
• Journal: Journal of cataract and refractive surgery (J Cataract Refract Surg) Vol. 48 Issue 9 Pg. 1063-1072 (09 01 2022) ISSN: 1873-4502 [Electronic] United States
• PMID: 35171145 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2022 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.

Topics

• Astigmatism
• Cataract
• Corneal Diseases
• Corneal Stroma
• Corneal Topography
• Humans
• Lasers
• Prospective Studies
• Refraction, Ocular
• Visual Acuity